If $\large\frac{2}{11}$ is the probability of an event,what is the probability of the event 'not A'

Question

$\begin{array}{1 1}(A)\;\large\frac{9}{11}\\(B)\;\large\frac{8}{11}\\(C)\;\large\frac{5}{11}\\(D)\;\large\frac{6}{11}\end{array} $